Detergent compositions containing metal discoloration inhibitors



Patented or. 18, 1952 DETERGENT COMPOSITIONS CONT :r 1

METAL DISCOLORATIGN llN m ITOR John a. Schaeiier, Reading, Ohio, assignor to The Procter and Gamble Company, Ivorydale, Ohio, a corporation of Ohio No Drawing. Application February a, 1969,

Serial No. 7%,712

kitchen ware, cutlery and household utensils resulting from dishwashing, for example. It is sometimes marked in soap dishes, constructed of these metals, which are exposed in bathroom or lavatory to the action of wet detergent bars. The surface layer of the bar also in some cases becomes discolored, and at times this discolored surface layer becomes detached from the bar and sticks to the metal surface.

. The discoloration phenomena which I have described appear in general when susceptible metals,

under sufficiently drastic conditions of concentration, time and temperature, are exposed to aqueous systems containing the class of anionic synthetic detergents or wettin agents which may be described as high molecular organic sulfonation products which possess pronounced surface active properties. Discoloration of the metals also appears when they are in contact with aqueous solutions of many inorganic salts, such as sodium or potassium chlorides or sulfates or the various water-soluble calcium-sequestering phosphates, and especially with detergent or wetting compositions comprising mixtures of these salts with surface active organic sulfonation products.

It is an object of this invention to provide means whereby such discoloration of metals may be minimized or prevented. It is a further object to provide new detergent and wetting compositions which have little or no tendency to cause discoloration of surfaces of copper, brass,- German silver and like susceptible metals. It is a further object to provide detergent compositions in bar form, which bars will not be subject to discoloration if kept in contact, while wet, with soap dishes or other surfaces of such metals.

Other obi ects will appear in the description whichfollows.

I have found that the objectionable discoloration phenomena. which I have described may in large measure be eliminated by incorporating in the detergent or wetting composition or dissolv- -manifest itself as a tarnished appearance upon ing in the aqueous solutions thereof small amounts of certain discoloration inhibitors. These inhibitors are compounds which possess a single heterocyclic ring structure of not less than 5 nor more than 6 members, the ring containing a linking nucleus which includes 3 members of the ring and which has one of the formulae:

and the ring being completed by satisfying free valence bonds of any two atoms of said linking nucleus by a polyvalent sulfonate-free organic residue, the members of the ring exclusive of the C: LBh-N Ethylene thiourea CHr-NH NN' trimethylene thiourea H Phenylene thiourea NHg-C-M Melamine N-NH I ii-amino-tetrazole O=C-NH C NH CEa- H-O -methyl-pseudohydantoln being used generically herein to designate the product of either of these reactions), thereby combining within themselves structures which both promote and inhibit metal discoloration, and such products I do not claim as discoloration inhibitors.

In order to be efiective, these inhibitors must be water-soluble, but the solubility need not be higher than is' required to produce inhibiting action at the particular temperature in question. In general, solubility decreases with increasing molecular weight, and while compounds of the specified structure having molecular weight above 250 are in some cases effective, I find that most inhibitors which are useful in practical applications are of molecular weight less than 250.

Many inhibitors of my invention also vary in eficiency at different temperatures for reasons which appear not to be attributable to solubility relationships. can be obtained by mixing the inhibitors. For example, good inhibition over a wide range of temperatures may be obtained by mixing an inhibitor which is most efiicient at lower temperature with one which is most eflicient at high temperature.

The efiectiveness and the water-solubility of the inhibitors may be afiected by the pH of the solution. Some of them, for example, are more efiective. at a high pH such as 10 or 11 than at a lower pH, while others of them are not stable in strongly alkaline solution and are less effective at the higher pH. By mixing inhibitors which are most effective at high pH with ones which are most effective. at low pH, I obtain good protecti'on over a wide range of pH values.

Partly because of considerations such as the above relative to solubility, temperature and pH, partly because of innate difierences in emciency among the inhibitors themselves, and partly also In such cases excellent results,

because of difierences in the nature of the metal and of the discoloring agent, the quantity of inhibitor required for effective action differs from case to case. In all cases the quantity required is small, being usually less than 0.01 per cent by weight of the aqueous ystem against which the metal is to be protected. I have in some cases observed that when the concentration of inhibitor exceeds an optimum value, emciency decreases, and I- therefore prefer in general to avoid using excessive amounts oi inhibitor, such as would give concentrations higher than about 0.01 per cent by weight in the aqueous system.

While metal discoloration can. be inhibited by adding the inhibitor to the water in which the surface active organic sulfonation product and/or the inorganic salts which cause discoloration are to be dissolved, or to the pre-iormed solution of these constituents, it is usually more convenient to premix the inhibitor with the sulionation product and/or inorganic salts. This may be done in conventional manner and at any time, for example by mechanically mixing the constituents or by milling them in the presence of a little water. The invention is not limited as to the means or method of incorporating the inhibitor nor as to the stage in the process of manufacturing the composition at which the incorporation takes place nor as to the physical form of the resulting non-discoloring composition. If, for example, the finished product is to be an essentially dry detergent powder, flake or granule, the inhibitor may be incorporated and uniformly dis tributed in an aqueous paste containing the other ingredients and this paste may be spray-dried or roll-dried in conventional manner. In case milled detergent ribbons or bars are desired, the inhibitor may if desired be incorporated during the milling procedure. It will be understood that" the composition containing the inhibitor may be in liquid, paste, powder, flake, bar or any other desired form.

The amount of inhibitor to be incorporated in the compositions of my invention should be sufflcient to inhibit discoloration when the said compositions are used in the normal manner for the purpose for which they are intended. Thus experience has shown that when detergent compositions comprising high molecular organic sulfonated detergents or mixtures thereof with water-soluble inorganic salts such as sodium chloride, sodium sulfate or calcium-sequestering phosphates are used for laundering or dishwashing purposes, or when such detergents or wetting agents are used in the textile industry, theconcentration of such composition in the solution rarely exceeds 1 per cent by weight, even in ex= Furthermore, as was pretremely hard water. viously stated, the concentration of inhibitor required in the solution in order to be effective is usually less than 0.01 per centby weight and effectiveness sometimes suflers it higher concentrations are used. In order therefore to have a detergent or wetting composition relatively free from objectionable discoloring action on metals, said compositions need rarely have an inhibitor content in excess of l per cent by weight.

In many cases 1 per cent inhibitor, based upon the total composition, is in excess of the amount necessary or desirable, in view inter alia of the cost of such inhibitors. For example, most such surface active organic sulfonated products in household use and many such detergents and wetting agents used in industry contain considerable quantities of inorganic salts and/or other materials and reduced quantities of suifonated organic matter. .Ineuch cases I find that effective discoloration inhibition is often attained with amounts of inhibitor equivalent to about 3 per cent or less byweight of the sulfonation aeiaeos 7 I product contained therein but not exceeding 1 per cent by weight of the total composition.

The surface active organic sulfonation product may be any of a number of different types. all of which are water-soluble salts which are characterized by having in their molecular structure a long chain lipophilic group of about 8 to about 24 carbon atoms and also either a sulfonic acid radical or a sulfuric acid ester radical or mixtures of such radicals, there being preferably only one such sulfonic acid or sulfuric acid ester radical per molecule.

Among such compounds are the water-soluble salts of the sulfuric reaction product of aliphatic. monohydric alcohols of about 10 to about 24 carbon atoms, and especially the water-soluble salts of sulfuric acid esters of normal primary aliphatic alcohols of about 10 to about 18 carbon atoms. such as those derived by reduction of coconut oil, cohune kernel oil, coquito nut oil, murumuru nut oil, ucuhuba nut oil, ouricuri oil, palm kernel oil, babassu oil or other oils of the coconut oil-group, a group of tropical nut oils more than half of the combined fatty acids of which are lauric and myristic. The sulfuric esters of high molecular alcohols from other oils, fats and waxes, of high molecular unsaturated aliphatic alcohols, of high molecular branched chain primary alcohols and of high molecular secondary alcohols may also be used in the compositions of my invention.

Other sulfuric esters which may be present in the compositions herein contemplated include water-soluble salts of sulfuric esters of polyhydric alcohols incompletely esterifled with high molecular monocarboxylic acids such as soap-forming fatty acids, cyclic acids such as those of rosin and tall oil and naphthenic acids, and synthetic acids such as may be obtained by oxidizing paraffln hydrocarbons or petroleum or by hydrogenating carbon monoxide (sometimes referred to as the Fischer-Tropsch process) or by oxidizing the saturated or unsaturated hydrocarbons or oxygenated hydrocarbons resulting from this process.

Specific examples of such detergents are the sulfonic acids (for example, sodium alkyl naph-' thalene sulfonate or'the sodium salt of the sulfonic acid derived by sulfonating the condensation product of benzene and a chlorinated kerosene fraction, such as represented by the formula BOsH in which R represents alkyl groups of from about 9 to about 15 carbon atoms) and water-soluble salts of ethers of high molecular alcohols and low molecular hydroxy alkyl sulfonic acids (for example, monolauryl ether of 1,2-dihydroxy-propane-3-sodium sulfonate, and lauryl ether of the sodium salt of isethionic acid) may be employed.

Certain inorganic salts have metal-discoloring properties when used in water even in the absence of sulfonated detergents of wetting agents, and they also contribute to the discoloration caused by the surface active sulfonated products herein referred to when present, as is frequently the case, in conjunction with them. Such contribution may assume importance when the amount of such salts, singly or in combination, exceeds about one per cent of the total weight of the composition. Metal discoloration caused by or contributed to a by these inorganic salts is also lessened by the sulfuric acid, and the sodium salt of lauryl ether of ethylene glycol sulfuric acid.

Similarly, water-soluble salts of sulfated higher fatty acid alkylolamides may be employed, such as the sodium salt of sulfated babassu oil fatty acid glycerol amide or of sulfated lauric amide of monoethanolamine.

,Grahams salt which is described in inhibitors of my invention. The most important of these inorganic salts appear to be alkali metal chlorides, sulfates phosphates, the sodium and potassium salts being the most common of these. By "calcium-sequestering phosphates I mean water-soluble salts of phosphoric acids which are poorer in water of constitution than orthophosphoric acid, such as tetrasodium pyrophosphate, pentasodium 4 triphosphate (sometimes referred to as tripolyphosphate), hexasodium tetraphosphate, hexasodium hexametaphosphate, as well as the various corresponding acid salts, such as disodium dihydrogen pyrophosphate, or the products ofadding small amounts of free acid to the completely neutralized salts. These salts are capable of repressing calcium ions in aqueous solutions. I place hexasodium tetraphosphate" and hexasodium hexametaphosphate in quotation marks to indicate that the salts so designated may be mixtures rather than pure chemical compounds. The tetraphosphate to which I refer is that compound or mixture which is described in U. s. Patent 2,031,827, and the hexam'etaphosphate" is the glassy variety sometimes called 1,956,515. Pater The metal-discoloring compositions which are improved by adding my inhibitors may vary widely in the relative proportions of the constituents. Thus the surface-active sulfonated products alone, although rarely encountered, produce some metal-discoloration; mixtures thereof with 1 per cent or more of the inorganic salts mentioned above are more common and are usually more and calcium-sequestering and powders or kitchen cleers. sometimes cause trouble. In general, my inhibitors find practical which 0.1 part of ethylene thiourea (based on the application in detergent or wetting urea;v

in composition from 1 per cent to 100- per itself and copper-containing alloys such as brass and German silver which I shall refer to as non-ferrous, coppery metals, as well as articles of such metals which are plated with imperfect coatings or worn coatings of non-discoloring metals, such for example as nickel or chromium. It will be understood, that various inhibiting compounds having the structures previously described may vary in effectiveness from metal to metal.

The following examples, in which all parts are by weight, illustrate the effectiveness of the discoloration inhibitors and ways in which I practice the invention, but it is to be understood that the examples are illustrative only and that the invention is not limited thereby but only by the terms of the appended claims.

Example 1.-80 parts of pentasodium triphosphate were mixed with parts of sodium salt of the sulfuric acid monoester of the monoglyceride of coconut fatty acids. A one-half per cent solution of this mixture was prepared in water, and sheets of German silver "918% nickel, 17% zinc and 65% copper) were partially submerged therein for 3 hours at 120 F. A colored tarnish .film soon appeared, golden at firstand eventually becoming dark blue or purple. Similar sheets, similarly submerged in a 0.5% solution of asimilar mixture to which 0.1 part of ethylene thiourea had been added developed only slightly tarnished appearance.

Verysimilar results were obtained when in place of the sulfated monoglyceride of the above example there was substituted:

(a) The sodium salt of a sulfonated alkyl benzene in which the alkyl group contained about 9 to about 15 carbon atoms, or

(b) The sodium salt of the sulfuric acid ester weight of the detergent composition) was added I remained nearly tranish-free.

Very similar results were obtained when in place of the ethylene thiourea of'the above example there was substituted 0.05 part of 2-a:-:.. :1. obenaothiazole or 3-amino-L2A-triazole.

Protective action in similar tests has been found for '(a) 0.02% ethylene thiourea, 2-aminobenzothiazole o'r 3-amino-1,2,4-triazole, or (b) 0.05% NN'-trimethylenethiourea or fi-methylpseudohydantoin, or (c) 0.1% -phenylenethiourea or melamine, or (d) 0.2% thiourazole or S-methyl mercapto-tetrazole, or (e) 0.5% of fi-propyl thiouracil, benzoylene thiourea, 3-mercapto-1,2,4- tetrazole, 2-aminobenzimidazole or creatinine when added to detergent compositions such as that of Example 2.

The composition of Example 2 is representative of commercial detergents comprising a mixture of waterluble calcium-sequestering phosphates, sodium sulfate, and high molecular organic sulfonation products which possess pronounced detergent power. Particularly efflcient compositions of this character comprise a mixture of calcium sequestering phosphates consisting predominantly (often about 75%) of pentasodiiun triplrcsphate but having a minor proportion {oiten about 25%) of tetrasodium pyrophosphate, a sodium alkyl sulfate in which the alkyl chain is that of a normal primary aliphatic alcohol of about 10 to about 18 carbon atoms, sodium sulfate in varying amount but commonly at least 10% by weight of the total, and a discoloration inhibitor, the ratio 'of the weight of the sulfonation product to the phosphates being about 1:1 to about 1:5, and the inhibitor being present in an amount not exceeding 1% by weight of the total composition, but suflicient to inhibit discoloration of metals when in contact with water and said composition.

The following examples illustrate the use of my inhibitors in detergent bars.- Example 3 is representative of bars comprising about.35 to 70 per cent by weight of water-soluble salts of sulfated fatty alcohols having more than 8 carbon 7 atoms in the alkyl radical, about 5 to 40% sodium of normal primary alcohols of about 10 to about 17 parts of sodium sulfate admixed wherewith were small proportions of sodium carbonate and other inorganic salts, and 8 parts of water.

Strips of brass and German silver as in Example 1 were suspended in a 0.5% solution of this mixture, becoming tarnished like those of Example '1 in the absence of ethylene thiourea. Strips suspended similarly in a. like solution to or potassium chloride or mixtures thereof, and

suificient organic bonding agent (such as mono and diglycerides of higher fatty acids, petroleum jelly and the like) to give plasticity to the bar but not exceeding one third thereof by weight. Bars of this general type are described'in Richard C. Wood's U. S. Patent No. 2,356,903.

Example 3.Milled bars comprising about 60% of soluble salts of sulfated coconut oil alcohols were prepared in conventional manner, about half of the remainder being a mixture of sodium chloride and sodium sulfate consisting predominantly of the former, and the rest being a mixture of petroleum jelly and monoglycerides derived from cottonseed oil. These bars, when used in normal manner in the bathroom and allowed to stand wet in worn metallic soap dishes caused the metal to discolor, and in addition the bars themselves became discolored in places of contact with'the metal. Similar bars were made; milling 0.1% -by weight of ethylene thiourea thereinto. These bars did not discolor nor did they cause discoloration of the soap dishes in normal household use in the bathroom.

The bars of Example 4 are representative of a class of detergent bars comprising a, mixture of water-soluble soap, water-soluble salts of sulfuric acid esters 'of normal primary aliphatic alcohols of about to about 18 carbon atoms. mono-alkylolamides of fatty acids of oils of the coconut oil group. and inorganic salts such as sodium chloride, sodium sulfate and mixtures thereof, the weight ratio of soap to sulfuric ester salt being about 0.5:1 to about 8:1, and that of sulfuric ester salt to amide being about 1:1 to about 10:1, the weight of amide being at least 2 per cent of the combined weights of soap. sulfuric acid ester salt and amide, the inorganic salts being present in an amount equal to about 1 per cent to about per cent by weight of the bar, and the bar being characterized by good cleansing and lathering power and resistance to the precipitating action of hard water.

Example 4.-Six parts of the monoethanolamide of coconut oil fatty acids, 70 parts of a conventional milled toilet soap base containing about 15% water, and 24 parts of a commercial alkyl sulfate powder containing about 88% sodium salt of sulfuric acid ester of coconut oil alcohols (the residue being largely sodium sulfate) were mixed with about 3 parts of water and milled in conventionalmanner to produce a homogeneous product which was then plodded and formed into bars. These bars, when used in normal manner in the bathroom and allowed to stand wet in soap dishes ofbrass imperfectly plated with nickel cause the soap dish to discolor and in addition the bars themselves become green in places of contact with the metal. Similar bars, contain-' ing 0.1% by weight of ethylene thiourea do not discolor appreciably nor cause appreciable discoloration when similarly used.

This application is a continuation-in-part of my application Serial No. 790,720, filed December 9, 1947, now abandoned.

.Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A surface active composition consisting essentially of a mixture of at least '1 per cent and not more than 98 per cent by weight of a water soluble detergent that is a salt of a high molecular organic sulfonation product of a material having in its molecular structure a long chain lipophilic group of from 8 to 24 carbon atoms, at least 1 per cent and not more than about 98 per cent by weight of an inorganic salt selected from the group consisting of sodium and potassium chlorides, sulfates, calcium-sequestering phosphates and mixtures thereof, and a discoloration inhibitor for non-ferrous, coppery metals which is a water-soluble organic compound of molecular weight not exceeding 250 and is characterized by a single heterocyclic ring of not less than 5 nor more than 6 members, said ring containing a linking nucleus which includes 3 members of said ring and is selected from the group consisting of nuclei of the formulae and said ring being completed by satisfying free valence bonds of any two atoms of said linking nucleus by a polyvalent sulfonate-free organic residue, the members of said ring exclusive of said linkin nucleus being selected from the group consisting of carbon and nitrogen, such free valence bonds as remain after completion of the ring being satisfied by a member of the group consisting of alkyl, aryl, aralkyl, alkylol and alkenyl radicals and'hydrogen. said inhibitor being present in an amount not exceeding 1 per cent by weight of the total composition and less than the amount of said sulfonation product but sumcient to inhibit discoloration of said metals when in contact with water and said composition.

2. The composition of claim 1 wherein the heterocyclic ring ofithe discoloration inhibitor is 5-membered and contains a linking nucleus of the formula 3. The composition of claim 2 wherein the discoloration inhibitor is ethylene thiourea.

4. The composition of claim 1 wherein the heterocyclic ring of the discoloration inhibitoris' 5-membered and contains a linking nucleus of the formula 5. The composition of claim 4 wherein the discoloration inhibitor is 2-aminoben2othiazole.

6. The composition of claim 1 wherein the heterocyclic ring of the discoloration inhibitor is 5-membered and contains a linking nucleus of the formula .NHC-l l- 7. The composition of claim 6 wherein the discoloration inhibitor is 3-amino-l,2,4-triazole.

8. The composition of claim 1 wherein the detergent is a water-soluble salt of the sulfuric reaction product of an aliphatic monohydric alcohol of about 10 to about 24 carbon atoms.

9. The composition of claim 1 wherein the detergent is a water-soluble salt of the sulfuric acid ester of primary straight chain aliphatic alcohols of about 10 to about 18 carbon atoms.

10. The composition of claim 1 wherein the detergent is a water-solublesalt of the sulfuric acid ester of alcohols derived from an oil of the coconut oil group.

11. The composition of claim 1 wherein the detergent is a water-soluble salt of a sulfonic acid of the formula wherein R. represents alkyl groups of about 9 to about 15 carbon atoms.

12. The composition of claim 1 wherein the detergent is a water-soluble salt of a sulfated monoglycerlde of the formula cnlosoln HOE 11,0001: where RCO represents acyl groups of fatty acids of about 10 to about 18 carbon atoms.

13. The composition of claim 1 wherein the inorganic salt is a sodium salt and is a calciumsequestering phosphate.

14. A detergent composition consisting essentially of at least 10 per cent by weight of sodium sulfate; a mixture of sodium phosphates consisting predominantly of pentasodium triphosphate and having a minor proportion of tetrasodium pyrophosphate; a water-soluble salt of a sulfuric acid ester of normal primary aliphatic alcohols having about 10 to about 18 carbon atoms, the ratio of the weight of sulfonation product to the sum of the weights of the phosphates being about 1:1 to about 1:5; and ethylene thiourea irran amount not exceeding 1 per cent by weight of the total composition and less than the amount of said sulfonation product but suihcient to inhibit discoloration of non-ferrous, -coppery metals when in contact with water and said composition.

15. A' detergent composition in bar form consisting essentially of about 35 to 70 per cent by weight of water-soluble salts of sulfated fatty alcohols having more than 8 carbon atoms in the alkyl radical, about to 40 per cent by weight of a salt of the group consisting of sodium and potassium chlorides, sulfates, calcium-sequestering phosphates and mixtures thereof, an organic bonding agent sufiicient to give plasticity to the and said ring being completed by satisfying free bar but not exceeding one-third thereof byselected from the group consisting of nuclei of the formulae and said ring being completed by satisfying free valence bonds of any two atoms of said linking nucleus by a polyvalent sulfonate-free organic residue, the members of said ring exclusive of said linking nucleus being selected from the group consisting of carbon and nitrogen, such free valence bonds as remain after completion of the ring being satisfied by a member of the group consisting of alkyl, aryl, aralkyl, alkylol and alkenyl radicals and hydrogen, the inhibitor being present in an amount not exceeding 1 p r cent by weight of the total composition but sumcient to inhibit discoloration of said metals when in contact with water and said composition.

16. The composition of claim 15 wherein the metal-discoloration inhibitor is ethylene thiourea.

17. A detergent composition in bar form consisting essentially of a water-soluble soap, watersoluble salts of sulfuric acid esters of normal primary aliphatic alcohols of about 10 to about 18 carbon atoms, the monoethanolamides of fatty acids of an oil of the coconut all group, an inorganic salt of the group consisting of sodium and potassium chlorides, sulfates, calcium-sequestering phosphates and mixtures thereof, and a discoloration inhibitor for non-ferrous coppery metals which is a water-soluble organic compound of molecular weight not exceeding 250 and is characterized by a single heterocyclic ring of not less than 5 nor more than 6 members, said ring containing a linking nucleus which includes 3 members of said ring and is selected from the group consisting of nuclei of the formulae valenc bonds of any two atoms of said linking nucleus by a polyvalent sulfonate-free organic residue, the members of said ring exclusive of said linking nucleus being selected from the group consisting of carbon and nitrogen, such free valence bonds as remain after completion of the ring being satisfied by a member of the group consisting of alkyl, aryl, aralkyl, allq'lol and alkenyl radicals and hydrogen, the weight ratio of soap to sulfuric ester salt being about 0.5:1 to about 8:1, and that of sulfuric ester salt to amide being about 1:1 to about 10:1, the weight of amide being at least 2 per cent of the combined weights of soap, sulfuric ester salt and amide, the inorganic salts being present in an amount equal to about 1 per cent to about 15 per cent by weight of the bar, andthe discoloration inhibitor not exceeding 1 per cent by weight ofthe bar and being suflicient to lessen discoloration thereof when wet and in contact with said metals.

18. As a new composition of matter, a mixture consisting essentially of a detergent water soluble salt of an organic compound having in its molecular structure a long chain lipophilic group 'of from 8 to 24 carbon atoms and a radical of and said ring being completed by satisfying free valance bonds of any two atoms of said linking nucleus by a polyvalent sulfonate-free organic residue, the members of said ring exclusive of said linking nucleus being selected from the group consisting of carbon and nitrogen, such free valence bonds as remain after completion of the ring being satisfied by a member of the group consisting of alkyl, aryl, aralkyl, alkylol and alkenyl radicals and hydrogen, said composition being one that causes discoloration of non-ferrous coppery metals in the absence of said inhibitor, said inhibitor being present in an amount not exceeding 1 per cent by weight of the total composition and less than the amount of said water soluble detergent but suflicient to inhibit discoloration of said metals when in contact with water and said composition.

JOHN R. SCHAEFFER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,773,024 Chapman Aug. 12, 1930 2,160,293 Shoemaker May 30, 1939 2,238,651 Keenen Apr. 15, 1941 2,327,323 Teeters Aug. 1'1, 1943 2,396,278 Lind Mar. 12, 1946 2,466,517 Blair Apr. 5, 1949 

1. A SURFACE ACTIVE COMPOSITION CONSISTING ESSENTIALLY OF A MIXTURE OF AT LEAST 1 PER CENT AND NOT MORE THAN 98 PER CENT BY WEIGHT OF A WATER SOLUBLE DETERGENT THAT IS A SALT OF A HIGH MOLECULAR ORGANIC SULFONATION PRODUCT OF A MATERIAL HAVING IN ITS MOLECULAR STRUCTURE A LONG CHAIN LIPOPHILIC GROUP OF FROM 8 TO 24 CARBON ATOMS, AT LEAST 1 PER CENT AND NOT MORE THAN ABOUT 98 PER CENT BY WEIGHT OF AN INORGANIC SALT SELECTED FROM THE GROUP CONSISTING OF SODIUM AND POTASSIUM CHLORIDES, SULFATES, CALCIUM-SEQUESTERING PHOSPHATES AND MIXTURES THEREOF, AND A DISCOLORATION INHIBITOR FOR NON-FERROUS, COPPERY METALS WHICH IS A WATER-SOLUBLE ORGANIC COMPOUND OF MOLECULAR WEIGHT NOT EXCEEDING 250 AND IS CHARACTERIZED BY A SINGLE HETEROCYCLIC RING OF NOT LESS THAN 5 NOR MORE THAN 6 MEMBERS, SAID RING CONTAINING A LINKING NUCLEUS WHICH INCLUDES 3 MEMBERS OF SAID RING AND IS SELECTED FROM THE GROUP CONSISTING OF NUCLEI OF THE FORMULAE 